SU1436868A3 - Method of producing tetronic acid - Google Patents

Abstract

1. Process for the preparation of tetronic acid from 4-chloroacetoacetic ester, characterized in that 4-chloroacetoacetic ester is converted into the 2,4-dichloroacetoacetic ester by chlorination, the latter is converted into 3-chlorotetronic acid by thermal treatment at temperatures of 110 to 1608C, and the latter acid is converted into tetronic acid by hydrogenation with hydrogen in the presence of a platinum metal catalyst.

Description

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The invention relates to the field of organic synthesis, specifically to a method for producing tetronone acid, an important intermediate of industrial organic synthesis.

The purpose of the invention is to increase the code of the desired product.

Example 1 C35., 90 g (2.00 mol) of 4-chloroacetoacetic acid Q ethyl ester is dissolved in 1000 ml of methylene chloride. Then, slowly at room temperature for 2.5 hours, 287.12 g (2.04 mol) of sulfuryl chloride was added dropwise. All the gas is completed in approximately 10 hours. The solvent is then distilled off on a rotary evaporator, after which the resulting yellow oily reaction product is dried under high vacuum. 20

405., 30 g of 2,4-dichloroacetoacetic acid ethyl ester (content according to GC-96, 1%) are obtained.

2,4-Dichloroacetic acid ethyl ester is heated for 2.5 hours at 140 C25 under reflux. This temperature has reached a bale} and has succeeded in doing so due to the reaction under reduced pressure.

Since 2,4-dichloroacetoacetic ester is consumed during the reaction, a constant temperature of the reaction of C11I is obtained only as a result of continuous decrease in pressure (90 degrees mbar at the beginning of the stage, 30 mbar at the end). The reaction mixture is allowed to cool9, and the solution solidifies. By adding 300 ml of toluene, the mixture is transferred to a stirred state. The injected 3-chlorotetronose acid is filtered on a putsch, washed with 500 ml of toluene and dried under high vacuum. 185.20 g of a slightly brown microcrystalline 3-chlorotetronic acid are obtained with a content of 99.3% (mp. 206 ° C) according to potentiometric titration 1 and NaOH. This corresponds to a yield of 68.4% based on 100% ethyl ether 4-Chloroacetoacetic acid. In order to recrystallize 170 g of 3-chlorotetronic acid in 3,400 ml of acetic ester is dissolved in a hot state and, together with 20 g of active charcoal, is refluxed for 2 hours. and the yellowish solution is concentrated to 100 ml.

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Example 2. In analogy to Example 1, 150.6 g (1 mol) of 4-chloroacetoacetic acid methyl ester is chlorinated at room temperature with equivalent amounts of sulfuryl chloride.

2,4-dichloroacetoacetic acid methyl ester is obtained in a quantitative yield of 185.5 g, the content is 93%. By subsequent heating for 3 hours under reflux at vacuum (95–70 mm Hg), gives 101.5 g of 3-chloroethonic acid at 75.5% yield with a content of 100%.

The processing is carried out according to Example 1. During the distillation of the mother liquor, 11.8% of the product is recovered.

The reaction of the reaction with the production of tetronic acid is carried out analogously to example 1,

Example 3. Analogously to Example 1, 226.7 g (1 mol) of 4-chloroacetoacetic acid benzyl ester is chlorinated at room temperature using equivalent amounts of sulfuryl chloride.

The benzyl ester of 254-dichloroacetoacetic acid is obtained in a quantitative yield of 261.5 g, the content of 94.1%. Subsequent heating for 2 hours under reflux at 130 ° C under vacuum (25-60 mmHg) gives 89.2 g of 3-chlorotetronic acid in 66.3% yield with a content of 99.9%.

Processing and further interaction with obtaining tetronic acid is carried out analogously to example 1,

EXAMPLE 4 Analogously to Example I, 220.7 g (1 mol) of 4-chloroacetoacetic acid hexyl ester is chlorinated with equivalent amounts of sulfuryl chloride at room temperature.

2,4-Dichloroacetoacetic acid hexyl ester is obtained in a quantitative yield of 255.3 g, the content is. Then it is heated for 3j5 h under reflux under vacuum (30-55 1 hm mer. Art.) To obtain 88.5 g of 3-chlorotetronic acid in 65.8% yield and 99.7% content.

Processing and further processing to obtain tetronic acid is carried out analogously to example 1.

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Example 5. Analogously to Example 1, 164.6 g (1 mol) of ethyl, 4-chloroacetoacetic acid ester is chlorinated using equivalent amounts of sulfurnyl chloride at 0 ° C.

2,4-dichloroacetoacetic acid ethyl ester is obtained with

with a yield of 199.8 g, content of 95.8%, then heated under reflux for 3 hours at 140 ° C under vacuum (30-60 mm p t.t.), obtaining 84.1 3-chlorotetronic acid with a yield of 62.5 % and content of 99.4%.

Processing and further processing to obtain tetronic acid is carried out analogously to example 1.

Example 6 Analogously to Example 1, 164.6 g (1 mol) of 4-chloroacetoacetic acid ethyl ester is chlorinated using equivalent amounts of sulfuryl chloride at 40 ° C.

The 2,4-dichloroacetoacetic acid ethyl ester is obtained in a quantitative yield of 199.7 g, content of 96, -3%.

Then, it was heated under reflux for 2 hours at 140 ° C under vacuum (25-50 mm Hg), yielding 94.0 g of 3-chloroetronic acid in 69.9% yield and 99.1% content.

Processing and processing to obtain tetronic acid is carried out analogously to example 1.

Example 7. Analogously to Example 1, 164.6 g (1 mol) of 4-chloroacetoacetic acid ethyl ester is chlorinated using equivalent amounts of sulfuryl chloride at room temperature. 2,4-Dichloroacetoacetic acid ethyl ester with quantitative code 199.2 is obtained. The content is 95.4%.

Then, it was heated under reflux for 2.5 hours at 160 ° C under vacuum (20-40 mm Hg) to obtain 86.5 g of 3-chloroetronic acid in a yield of 64.3% and a content of 99.6%.

The treatment to produce tetronic acid is carried out analogously to example 1.

Example 8. Analogously to Example 1, 164.6 g (1 mol) of 4-chloroacetoacetic acid ethyl ester is chlorinated at room temperature with the use of equivalent amounts of sulfuryl chloride.

2,4-dichloroacetoacetic acid ethyl ester is obtained in a quantity of

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199.6 g with a content of 96.0%.

Then 2.5 hours is heated under reflux at 110 ° C in vacuum (50-70 mmHg) to obtain 76.6 g of 3-chlorotetronic acid with a code of 56.9% and a content of 99.0%.

Processing and processing to obtain tetronic acid is carried out analogously to example 1.

Example 9. Analogously to example 1, receive 3-chlorotetronic acid. 50.0 g (0.37 mol) of 3-chloro-5 tetronic acid (99.4% content) are dissolved in 400 ml of water by adding 1.48 g of platinum on carbon (5%). Then hydrogenated at an initial pressure of 20 bar and room temperature. After 4.5 hours, the hydrogen uptake is complete.

After processing, similar to example 1, receive a white crystalline tetronic acid with code of 36.1 g (content of BISH, 0%).

 the yield of tetronic acid, calculated on the 4-chloroacetoacetic acid ethyl ester used, is 64.9%.

Example 10. Similarly, with measure 1, 3-chlorotetronic acid is obtained. 50.0 g (0.37 mol) of 3-chlorophenol acid (99.4% content) are dissolved in 400 ml of water with the addition of 1.42 g of rhodium on carbon (10%). Then hydrogenated at an initial pressure of 3.5 bar and. After 10 h, the absorption of hydrogen is complete.

After processing, similar to example 1, get a white crystalline tetronic acid with a yield of 30.9 g. The content of BISH is 98.9%.

The total yield of tetronic acid, based on the 4-chloroacetoacetic acid ethyl ester used, is 55.6%.

Example 11. Analogously to Example 1, 3-chlorotetronic acid is used. 50.0 g (0.37 mol) of 3-chlorotetronic acid (99.4% content) are dissolved in 400 ml of water with the addition of 1.50 g of palladium on pumice (5%). Then hydrated at an initial pressure of 6 bar and room temperature. After 6.5 h, the absorption of hydrogen is stopped.

After processing as in Example 1, a white crystalline tetronic acid is obtained with the yield

33.9 g. Content (BISH) 99.1%,

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The total yield of tetronic acid, based on the ethyl ester used, of 4-chloroacetoacetic acid is 60.9%.

Example 12. Analogously to Example 1, 3-chlorotetronic acid. 50JO g (0.37 mol) of 3 chlorotethonic acid (with a content of 99.4%) is dissolved in 400 ml of water with the addition of 1.45 g of palladium on alumina (5%), followed by hydrogenation at an initial pressure of 7 bar and room temperature. temperature After 7 h, the absorption of hydrogen is stopped.

After processing in analogy with Example 1, white crystalline tetronic acid is obtained with an inlet of 34.8 g and a content (BISH)

The total yield of tetronic acid, based on ethyl 4-chloroacetoacetic acid ethyl ester used, is 62.5%.

Example 13. Analogously to Example 1, 3-chlorotetronic acid is obtained.

50.0 g (0.37 mol) of 3-chlorotrotonic acid (99.4%) are dissolved in 400 ml of water with the addition of 1.49 g of palladium on silica gel (5%). Then it is hydrogenated at an initial pressure of 7 bar and at room temperature. After 75.5 hours, the absorption of hydrogen is stopped.

After processing as in Example 1, 34.4 g of white crystalline tetronic acid with a content (BISH) of 99.2% are obtained.

The total yield of tetronic acid, based on the 4-chloroacetoacetic acid ethyl ester used, is 61.8%.

Example 14. Analogously to example 1, get 3-chlorotetronovoy kis

lotu. 50.0 g (0.37 mol) of 3-chlorotethonic acid (content 99 (4%) is dissolved in 400 ml of water with the addition of 1.44 g of palladium on carbon (5%). Then hydrogenated at an initial pressure of 7 bar and at 0 ° C. After 9 h, the absorption of hydrogen ceases.

After processing, similar to example 1, get 33.2 g of white crystalline tetronic acid, the content (BISH) of 98.9%. The total yield of tetronic acid, calculated on the 4-chloroacetoacetic acid ethyl ester used, is 59.7%.

Claims (1)

Invention Formula A method of producing tetronic acid using halogenation of an acetoacetic acid derivative followed by pyrolysis of the resulting dihalide derivative to form 3-haloetronic acid, which is hydrogenated with hydrogen in the presence of a catalyst, on the basis of a platinum group metal, taken in an amount of 2-10% on a carrier, about one liter and so that, in order to increase the yield of the target 4-chloro-aceto-acetic C-C-alkyl ester is used as a derivative of acetoacetic acid. halogenation is carried out with sulphuryl chloride at 0–40 ° C to form 2,4-dichloroacetoacetic ester, pyrolysis is carried out at 110–160 ° C to obtain 3-chlorotetronic acid, and the hydrogenation is carried out at 0–30 ° C under a pressure of 3.5–20 atm using platinum group or palladium or rhodium as the metal, and pumice as the carrier, or alumina, or silica gel, or coal.